As bandwidth requirements for applications increase at rapid rates, they depend on DSPs to provide the real-time signal processing. DSP applications that perform this real-time processing have hard real-time I/O requirements. A DSP with Serial RapidIO (sRIO) capabilities can meet these bandwidth requirements. There are two approaches in using sRIO to dramatically increase I/O bandwidth: direct I/O or messaging passing.
The direct I/O approach, where data is read or written by specifying the target and the address, provides the highest performance. This approach is ideal for applications where target buffering is known and partitioning is fixed. Data movement works like a DMA engine, and packet efficiencies of up to 96% are achievable.
Message passing, on the other hand, is the more abstract way to communicate, using mailboxes and letters supported by the target. It's optimal for applications where the target buffering scheme is unknown and the application partitioning is unknown or flexible. It eliminates the need to address low-level data movement, application partitioning, and target buffering, which ultimately reduces time-to-market, especially on complex topology applications.
In addition, message-passing application programming interfaces provide powerful
programming features, such as the ability to move readers and writers around
processors without needing to modify source code. This makes it possible to
develop on a single processor and to easily scale to a multiple processor system.